Method of hydrogen production with particular reference to the hydrogenation of oils



Patented Apr. 17, 1934 UNITED STATES PATENT OFFICE Robert T. Haslam, Westfield, N. 1., assignor to Standard Oil Development Company, a corporation ol. Delaware No Drawing. Application October Serial No. 566,814

8 Claims.

My invention relates to the hydrogenation of hydrocarbon oils, and more particularly to the production of hydrogen from heavy corbona ceous materials, including hydrocarbons, and to 5 the use of this hydrogen in the hydrogenation and especially the destructive hydrogenation of oils.

In the hydrogenation of hydrocarbon oils under high pressure it is known that those hydrocarbons which may be vaporized without decomposition at atmospheric or reduced pressures are preferable as feed stocks especially when highly anti-knock gasoline is required, and that it is preferred to eliminate the very heavy, viscous or tarry fractions from the feed stocks. These heavy fractions have heretofore been considered of lesser value, and have been used either for fuel as the simplest means of disposing of an undesirable waste product, or as a feed stock for destructive hydrogenation to produce light gas oils suitable for anti-knock gasoline production.

I have now found an additional means of utilizing this waste material in the preparation of hydrogen of such purity that it is suitable for use in high pressure hydrogenation processes.

According to my invention it is now possible to prepare hydrogenated petroleum products with only petroleum oil as a source of both hydrogenation feed stock and of hydrogen. In my invention I take a crude petroleum oil, or any liquid hydrocarbon material containing volatile and substantially non-volatile fractions, and separate it by distillation or destructive distillation, with or without steam and/or the use of vacuum, into fraction consisting of the lower boiling material and the other of higher boiling, very diflicultly volatile or subtantially non-volatile residue. I prepare hydrogen from the non-volatile or very high boiling fraction in a manner hereinafter described, and I pass the lighter fraction, with this hydrogen, over suitable active catalysts at elevated temperatures and pressures which are adjusted according to the extent of the hydrogenation and the nature of the products desired, as will be understood from the known art.

The production of hydrogen from hydrocarbons and steam at suitably elevated temperatures has long been known. The preferred catalystsv for this reaction consist essentially of nickel or cobalt admixed with suitable activators. With such catalysts it is desirable to use reacting materials substantially free of all sulphur compounds and various methods have been proposed two fractions according to boiling range, oneasphaltic residuums is therefore undesirable because of both the heavier hydrocarbons and the sulphur compounds. The removal of hydrogen sulphide from such stocks or their gasification products is comparatively simple but carbon disulphide, carbon oxysulphide and the heavier organic sulphur compounds are exceedingly difficult to remove, and usually require catalytic processes which will be described below. The presence of heavier saturated and unsaturated hydrocarbons aggravates the difficulties of sul- 7 phur removal. Such hydrocarbons, by carbon deposition, polymerization or other means, readily poison the desulphurization catalysts.

In my process, after separating the heavier fractions from the relatively lighter oil which is to be later hydrogenated, I convert them to a fixed gas containing inappreciable amounts of heavier hydrocarbons and a sulphur content consisting largely of hydrogen sulphide. The sulphur compounds are then removed and the purified gas is subjected to a catalytic process for converting the residual hydrocarbons, mainly methane, to hydrogen.

The gasification of the heavier fraction is conducted at relatively high temperatures of about 1600 to 2500 F. or higher and I find either the packed refractory chambers such as are used for the production of carbon black by thermal decomposition of hydrocarbons, or the standard type of water-gas set comprising a chamber filled with coke, which may be a solid residue from the destructive distillation of hydrocarbons, followed by carburetors or chambers packed with refractory material, as satisfactory types of apparatus.

While the heavy hydrocarbon oils are especially adapted for use in my hydrogen production process, lighter hydrocarbons such as gas oil, burning oil, naphthas and even gases such as cracked petroleum gases may also be used.

In operating with liquid hydrocarbons such as fuel oil, the following process may be used in a water-gas generator and a carburetor, both being connected at the bottom:

A coke fire is built in the generator and blown for the removal of such compounds from the hot according to usual water gas practice. The

air-blow is shut off, the generator is purged with steam and then a heavy asphaltic fuel oil is sprayed with or without steam on top of the fuel bed with a down draft, the fuel bed being thick enough and hot enough to decompose the tar and oil so that a fixed gas, consisting mainly of C0, C02, H2 and low molecular weight hydrocarbons, passes from the bottom of the generator over into the bottom of the carburetor. Additional steam may then be added and the gas is passed into the carburetor, previously heated to temperatures above about 1800 or 2000 E, where the heavier hydrocarbons are converted almost completely into methane, oxides of carbon, and hydrogen. Some carbon may be deposited in the carburetor, and is subsequently burned off during the heating blow. The refractory packing material of the carburetor may be impregnated or coated with suitable catalysts and I find that a coating of mixed nickel and aluminum oxides is very advantageous.

In place of the water-gas set a series of packed refractory chambers suitably heated to incandescence, as by first blowing with air and fuel, may be used. For example, after the initial heating of such chambers, finely atomized oil fuel may be sprayed into the first chamber and there decomposed substantially into hydrogen, light gaseous hydrocarbons and carbon which under proper conditions of operation remains almost entirely on the refractory. Steam may be added to the gases entering the successive chambers which may be substantially similar both in construction and operation to the carburetor already described. If desired, the addition of steam may be omitted, and a substantially pure hydrogen, suitable for high pressure hydrogenation, may then be produced directly by the-decomposition of the heavy oil into hydrogen and carbon. The carbon deposited in the chambers is then burned oil? in the air-blow at the beginning of the next cycle and forms at least a partial source of fuel for the heating blow. Pure oxygen may be supplied with the hydrocarbons and in such operation sufiicient heat may be liberated so that alternate blowingv with an air-fuel mixture is unnecessary. Air, or other oxygen and nitrogen mixtures may be supplied with the hydrocarbons, and the resulting gas may be used in ammonia synthesis.

The gas from any of the above operations,

. which may be considered as a first stage in my process, is then treated to remove any entrained carbon and, if the gas must later be purified of hydrocarbons, to remove substantially all of the sulphur compounds contained therein. The entrained carbon may be removed by a hot filter, a

,water wash, electrical precipitation, or other standard methods. The sulphur may be removed which may then be removed by scrubbing with out excessive heat loss for cooling and reheating. The purified gas may then be passed without added heat directly over hydrocarbon conversion and carbon monoxide conversion catalysts. In many cases the amount of organic sulphur in the gas will be negligible and the hydrogen sulphide may be removed as described without the necessity of other treatments for organic sulphur removal. Of course, if the sulphur content is small, or catalysts insensitive to sulphur are used in the subsequent steps, the desulphurization may be eliminated.

The purified gas is then suitable for reaction with steam or carbon dioxide over activated nickel, or other suitable hydrocarbon conversion catalysts, for substantially complete elimination of the residual methane and such small amounts of heavier hydrocarbons as may be present. This process is well known and may be conducted, for example, as described in the co-pending application Ser. No. 389,340 of Young, Hanks and Freyermuth, filed August 30, 1929. If the gas from the first step of my process contains suflicient CO: or steam for reaction with the residual methane therein, the addition of extra CO2 or steam may be unnecessary in this step.

The purified gas may also be used, either before or after the conversion of the residual hydrocarbons, for the synthesis of alcohols, esters and the like. It is understood that if such use is intended the first steps of my process, and the hydrocarbon conversion, will be conducted under conditions favoring a relatively large proportion of carbon monoxide in the final gas.

A suitable catalyst for this step comprises a mixture of nickel, aluminum and magnesium oxides in substantially molal proportions. The gas from this step consists essentially of H2, CO and CO2, and is passed over suitable catalysts such as iron oxide for the conversion of carbon monoxide with steam to hydrogen and carbon dioxide. The carbon dioxide may then be removed by suitable scrubbing liquids such as triethanolamine or sodium carbonate solutions, or water. The use of elevated pressures aids the removal of carbon dioxide especially with soda solutions or water. The final gas comprises mainly hydrogen with usually less than 5% of impurities such as unconverted hydrocarbons, carbon dioxide, carbon -monoxide, or nitrogen, and is suitable for the hydrogenation of carbonaceous materials.

In my improved process I use this hydrogen for the hydrogenation, preferably at elevated pressures and temperatures. of the relatively lower boiling fractions which were separated by 130 distillation from the residue used for hydrogen manufacture. My process accordingly makes it possible to prepare hydrogenated products such as anti-detonating gasolines, high quality burningoils and lubricating oils, without the necessity of a supply of natural gas or other hydrocarbon gases or industrial gases heretofore required.

The hydrogenation step is conducted under conditions of pressure, temperature and type of catalyst selected according to the type of product 140 desired, as will be understood. In general, I prefer to use pressures above about 20 or 50 or even 200 atmospheres and sulfactive catalysts such as the oxides or sulphides of the metals of the VI group of elements, with suitable activators.

My invention is not to be limited to any illustrative examples nor theory of the operation, but only by the following claims in which I claim all novelty as far as the prior art permits. 150

I claim:

1. An improved process for the production oi hydrogen from hydrocarbons heavier than methane containing sulphur comprising passing the hydrocarbons with added steam over an incandescent solid to produce a gas containing an inappreciable amount of hydrocarbons heavier than methane, removing sulphur from said gas, passing the purified gas over hydrogen production catalysts for conversion of residual hydrocarbons to hydrogen and oxides of carbon, and removing the oxides of carbon.

2. Process according to claim 1 in which the hydrogen is produced by passing a liquid hydrocarbon iracticn over an incandescent solid, and

the carbonaceous product or thermal decomposi tion is separated from the resulting gas.

3. An improved process for the 'production of hydrogen from liquid hydrocarbon mixtures containing sulphur compounds comprising subjecting the mixture to a temperature above about 1600 F. to produce a gas containing lnappreciable amounts of hydrocarbons heavier than methane, removing sulphur from said gas with out substantial cooling and passing the hot purifled gas over active sulphur sensitive catalyst for the conversion of the methane to hydrogen and oxides of carbon.

4. An improved process for the production 0! hydrogen comprising passing a heavy hydrocarbon oil of the class of crude oil, fuel oil or gas oil over an incandescent solid, and producing a gas containing hydrogen, low molecular weight lwdrocarbons and carbomremcving the carbon from said gas and passing the gas without substantial cooling over suitable catalysts for the conversion or organic sulphur compounds to hydrogen sulphide and then at the same temperature over suitable absorbents for the hydrogen sulphide, passing the purified gas with added steam over suitable catalysts for conversion of the low molecular weight hydrocarbon to hydrogen and oxides of carbon and then over suitable catalysts for conversion of carbon monoxide to carbon dioxide and removing the carbon dioxide with a suitable absorbent.

5. Process according to claim din which the hydrogen is produced without the application of external heat following the step comprising passing the higher boiling fraction of the heavy hydrocarbon oil over an incandescent solid.

6. Process according to claim 4 in which the higher boiling fraction or the heavy hydrocarbon oil is passed with added steam over an incandescent solid, and a gas is produced containing hydrogen, water vapor, low molecular weight hydrocarbons, oxides of carbon, and carbon, and the successive steps including the conversion oi. carbon monoxide to carbon dioxide are conducted without added heat.

7. An improved process for the production or hot hydrogen of great purity comprising passing an impure hydrocarbon containing sulphur over an incandescent solid to produce substantially complete reaction to hydrogen, carbon, and sulphur compounds, removing the carbon and passing the gas without added heat over suitable catalysts for the conversion to hydrogen sulphide or all sulphur compounds and then without cooling over suitable absorbents for the hydrogen sulphide, withdrawing a hot substantially pure hydrogen tree from sulphur compounds.

8. Process for treating a petroleum oil, comprising separating said oil into relatively light and heavy fractions, passing said heavy traction over an incandescent solid to produce a gas containing hydrogen and low molecular weight hydrocarbons, removing sulphur from said gas, passing the purified gas with steam over a hydrogen production catalyst for conversion of hydrocarbons to hydrogen and oxides oi carbon, removing said oxides 01' carbon and bringing the resulting gas into contact with said light traction of said petroleum oil at an elevated temperature and pressure suitable for high pressure hydrogenation oi. said oil.

ROBERT T. HABLAM. 

